Discharger for a flowable medium

ABSTRACT

1. Discharger.  
     2.1. The invention relates to a discharger for a flowable medium, comprising a discharge sleeve ( 20 ), at whose one end there is provided a discharge opening ( 22 ) for discharging the medium, and a closing pin ( 30 ), which is provided in the discharge sleeve ( 20 ) and is longitudinally displaceable relative to the discharge sleeve ( 20 ) and by which the discharge opening ( 22 ) can be closed off.  
     2.2 According to the invention, the closing pin ( 30 ) has an outward-pointing cylindrical sub-portion ( 30   a ) and the discharge sleeve ( 20 ) has an inward-pointing cylindrical sub-portion ( 20   a ), the cylindrical sub-portions ( 20   a   , 30   a ) forming a transition fit or a tight clearance fit and a pressure-reducing and/or medium-flow-reducing working geometry ( 34 ) being provided in the cylindrical sub-portion ( 20   a   , 30   a ) of the closing pin ( 30 ) and/or of the discharge sleeve ( 20 ). 2.3 Use for mediums which are intended to be discharged with low pressure and without a pronounced spray jet.

FIELD OF APPLICATION AND PRIOR ART

The invention relates to a discharger for a flowable medium, comprisinga discharge sleeve, at whose one end there is provided a dischargeopening for discharging the medium, and a closing pin, which is providedin the discharge sleeve and is longitudinally displaceable relative tothe discharge sleeve and by which the discharge opening can be closedoff.

Dischargers with designs of this type are known. One drawback with theseis that a high medium pressure is generally present within the dischargesleeve before the closing pin opens up the discharge opening. Uponopening, this pressure results in a spray jet, which, according to thepurpose of use, is meant to be prevented.

PROBLEMS AND SOLUTIONS

The object of the invention consists in refining the dischargers knownfrom the prior art, particularly with regard to an improved spraypattern.

This object is achieved by a discharger of the generic type in which theclosing pin has an outward-pointing cylindrical sub-portion and thedischarge sleeve has an inward-pointing cylindrical sub-portion, thecylindrical sub-portions forming a transition fit or a tight clearancefit and a pressure-reducing and/or medium-flow-reducing working geometrybeing provided in the cylindrical sub-portion of the closing pin and/orof the discharge sleeve.

The working geometry is achieved, in particular, by a configurationhaving a small cross section through which the medium must flow. Itthereby limits the fluid flow. This is particularly relevant in respectof mediums which are to be applied to an eye, since a strong spray jetcaused by a large fluid flow is undesirable in this particularapplication. The working geometry which is provided according to theinvention constitutes an advantageous and constructionally simplesolution to the reduction of the fluid flow. This is advantageous, inparticular, in dischargers whose discharge opening is opened independence on a medium pressure. It is particularly advantageous if themedium-flow-reducing geometry is adjoined by a diffuser in which theincreased pressure is reduced again.

The configuration comprising cylindrical sub-portions means that theeffect of the working geometry is not dependent on the relative positionof the closing pin to the discharge sleeve, as would be the case, forexample, with conical sub-portions whose spacing likewise changes as aresult of an axial change of position.

In one refinement of the invention, the closing pin is longitudinallydisplaceable, in dependence on a fluid pressure of the medium, in apumping chamber of a pumping device of the discharger and closes off thedischarge opening if the fluid pressure of the medium is below a definedlimit pressure. In this type of pressure-dependent closing pin control,the configuration according to the invention is particularly expedient,since the high pressure which is necessary for the relative displacementof the closing pin increases the risk of a problematic spray pattern.

In one refinement of the invention, the cylindrical sub-portion of theclosing pin and/or of the discharge sleeve contains at least one mediumduct. Such a medium duct constitutes a very simple form of a workinggeometry. The medium duct is preferably provided on the cylindricalsub-portion of the closing pin, since a removal from the mold duringmanufacture can then more easily be realized. In the simplest case, themedium duct extends axially parallel to the direction of displacement ofthe closing pin.

In a particularly preferred embodiment, the medium duct extendshelically. Such an extent yields two advantages.

In the first place, a long medium duct is thereby attainable in spite ofonly short cylindrical sub-portions. In the second place, the mediumduct having an outlet direction with a tangential component incombination with an adjoining chamber in front of the outlet openingacts at the same time as a diffuser, which latter reduces the pressureand velocity upon exit from the outlet opening.

In one preferred refinement of the invention, the closing pin isoperatively connected to a pressure plate which can be actuated by theinternal pressure, the closing pin preferably being configured in onepiece with the pressure plate. Such a pressure plate allows theattainment of the intrinsically conflicting goals of the displacement ofthe closing pin at only low medium pressure, on the one hand, and thepressurization of the closing pin in the closing direction with a highspring force. As a result of its large surface area, the pressure plateleads to the opening force which opposes the spring force being achievedeven by low pressure. This too helps to improve the medium discharge.For this purpose, the pressure plate surface area is preferably at leastfive times, preferably ten times larger, than the surface area of thedischarge opening.

It is particularly preferred if the pressure plate consists at leastpartially of an elastic material, preferably of a material having anE-modulus below 1 kN/mm², in particular having an E-modulus below 0.5kN/mm². The elasticity leads to transient pressure peaks of the mediumpressure being absorbed by the pressure plate. This leads to improvedopening characteristics of the discharge device. In particular, thecombination of an inventive working geometry with an elastic pressureplate has proved very well-suited to ensuring an advantageous spraypattern.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages and features of the invention emerge from the claimsand the following description of a preferred illustrative embodiment ofthe invention, which is represented with reference to the drawings inwhich:

FIG. 1 and 2 show a discharge device according to the invention in apartially sectioned perspective representation and a partially sectionedside view, only that part of the discharge device which is relevant tothe invention being represented.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

FIG. 1 and 2 show a portion 10 of a discharger according to theinvention in a partially sectioned perspective representation and apartially sectioned side view.

The portion 10 comprises a discharge sleeve 20, which, in therepresented embodiment, is configured in one piece with a housing(otherwise not represented) of the discharger, and a closing pin 30,which is disposed in the discharge sleeve 20 and the lower end of whichis adjoined by an integrally attached pressure plate 40.

The discharge sleeve 20 has at its upper end a discharge opening 22,through which medium can escape when the discharger is used. In thenon-actuated state of the discharger, this discharge opening 22 isclosed off by a sealing portion 32 disposed at the upper end of theclosing pin 30. The closing force is applied by a valve spring (notrepresented), which forces the unit comprising closing pin 30 andpressure plate 40 jointly upwards in the direction 2.

A discharge process is triggered by the pressure in an interspace 50between the discharge sleeve 20 and the unit comprising closing pin 30and pressure plate 40 being increased by means not represented indetail, in particular by a pump. This increased pressure acts upon thepressure plate 40 in a sub-region 50 a, a slightly increased pressure,owing to the relatively large surface area of the pressure plate 40,producing a substantial opening force in a direction opposite to thedirection 2. This opening pressure brings about a relative displacementof the closing pin 30 relative to the discharge sleeve 20 and thus anopening of the discharge opening 22.

In a region 60, the discharge sleeve 20 and the closing pin 30 havemutually matched cylindrical sub-portions 20 a, 30 a. The externaldiameter of the cylindrical sub-portion 30 a of the closing pin 30 andthe internal diameter of the cylindrical sub-portion 20a of thedischarge sleeve 20 form a tight clearance fit. In the cylindricalsub-portion 30 a of the closing pin 30 there is provided a helical 34groove, which forms a duct 34 for the escaping medium. Owing to thetight clearance fit, the medium is able to make its way from theinterspace 50 to the discharge opening 22 only through this groove 34.

When the discharger is actuated, the closing pin 30, in a manner notrepresented in detail in FIG. 1 and 2 and as a result of an increasedfluid pressure of the medium, is displaced relative to the dischargesleeve 20 counter to the direction 2, so that the discharge opening 22is opened up by sealing portion 32 at the upper end of the closing pin30. The pressurized medium then makes its way through the groove 34 tothe open discharge opening 22, the groove reducing the fluid flow of themedium in the style of a throttle valve. The fluid flow escapes at theupper end from the groove 34 into an interspace 52, which acts as adiffuser. In this interspace, the fluid pressure is decreased and themedium is released with reduced pressure through the discharge opening22.

In a non-represented embodiment, the groove is provided in thecylindrical portion on the discharge sleeve instead of in the cylinderportion of the closing pin. Moreover, other configurations are alsopossible, in the simplest case, for example, grooves which are straightand orientated in the longitudinal direction of the closing pin.

1. Discharger for a flowable medium, comprising a discharge sleeve (20),at whose one end there is provided a discharge opening (22) fordischarging the medium, and a closing pin (30), which is provided in thedischarge sleeve (20) and is longitudinally displaceable relative to thedischarge sleeve (20) and by which the discharge opening (22) can beclosed off, characterized in that the closing pin (30) has anoutward-pointing cylindrical sub-portion (30 a) and the discharge sleeve(20) has an inward-pointing cylindrical sub-portion (20 a), thecylindrical sub-portions (20 a, 30 a) forming a transition fit or atight clearance fit and a pressure-reducing and/or medium-flow-reducingworking geometry (34) being provided in the cylindrical sub-portion (20a, 30 a) of the closing pin (30) and/or of the discharge sleeve (20). 2.Discharger according to claim 1, characterized in that the closing pin(30) is longitudinally displaceable, in dependence on a fluid pressureof the medium, in a pumping chamber of a pumping device of thedischarger and closes off the discharge opening (22) if the fluidpressure of the medium is below a defined limit pressure.
 3. Dischargeraccording to claim 1, characterized in that the cylindrical sub-portion(20 a, 30 a) of the closing pin (30) and/or of the discharge sleeve (20)contains at least one medium duct (34).
 4. Discharger according to claim3, characterized in that the medium duct (34) extends helically. 5.Discharger according to claim 1, characterized in that the closing pin(30) is operatively connected to a pressure plate (40) which can beactuated by the internal pressure, the closing pin (30) preferably beingconfigured in one piece with the pressure plate (40).
 6. Dischargeraccording to claim 5, characterized in that the pressure plate (40) apressure plate surface area which is at least five times, preferably tentimes larger, than the surface area of the discharge opening (22). 7.Discharger according to claim 5, characterized in that the pressureplate (40) consists at least partially of an elastic material,preferably having an E-modulus below 1 kN/mm², in particular having anE-modulus below 0.5 kN/mm².